M5.5 earthquake 161 km NNW of Houma, Tonga
A magnitude 5.5 earthquake struck 161 km NNW of Houma, Tonga on Sat, Jun 28, 2025, 5:17 PM GMT+13 (04:17 UTC), 229 km (142 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.5 (Mww, W-phase moment), moderate
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2025-06-28 04:17:08 UTC
- Depth
- 229.0 km (142.3 mi), intermediate-depth
- Epicenter
- 19.882° S, 176.034° W
- Region
- Tonga
- Strongest shaking
- III, weak shaking
- PAGER alert
- Green
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Magnitude estimates
Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.
| Mag. | Scale | Computed by | Notes |
|---|---|---|---|
| 5.5 | Mww, W-phase moment | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.054 · 33 stations |
| 5.8 | Mi | NOAA Pacific Tsunami Warning Center | First automatic solution · Reviewed · 12 stations |
| 5.6 | Mwb, body-wave moment | USGS National Earthquake Information Center | Moment tensor · Reviewed |
| 5.5 | Mww, W-phase moment | USGS, automatic first solution | First automatic solution · Confirmed |
Shaking
The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.
- Strongest estimated
- III, weak shaking
- Peak ground acceleration
- 0.5% of gravity
- Peak ground velocity
- 0.3 cm/s
- Map
- Automatic
Did you feel it?
No one has reported feeling this quake to the USGS.
Estimated impact
The USGS PAGER system estimates deaths and economic losses from the shaking and the population and buildings exposed to it.
- Alert level
- Green: little or no damage or loss of life expected
| Range | Chance |
|---|---|
| Under 1 | 65% |
| 1 to 10 | 30% |
| 10 to 100 | 4% |
| 100 to 1,000 | Under 1% |
| 1,000 to 10,000 | Under 1% |
| 10,000 to 100,000 | Under 1% |
| 100,000 to 10,000,000 | Under 1% |
| Range, million USD | Chance |
|---|---|
| Under 1 | 65% |
| 1 to 10 | 30% |
| 10 to 100 | 4% |
| 100 to 1,000 | Under 1% |
| 1,000 to 10,000 | Under 1% |
| 10,000 to 100,000 | Under 1% |
| 100,000 to 10,000,000 | Under 1% |
Fault motion and ground failure
How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.
- Faulting
- Normal
- Moment magnitude
- 5.5 Mww
- Nodal plane 1
- Strike 12°, dip 80°, rake -107°
- Nodal plane 2
- Strike 252°, dip 19°, rake -31°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 9.9 km horizontally, 1.9 km in depth
- Magnitude uncertainty
- ±0.05
- Depth from
- From modeling of broad-band P waveforms
- Station coverage gap
- 74°
- Stations used
- 75
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 2.5 and up: 2 in the 60 days after this one and 3 in the 30 days before it.
After
- 4.6215 km NW of Houma, Tonga · 433 days ago · 308 km deep · 58 km away
- 4.8145 km NNW of Houma, Tonga · 425 days ago · 171 km deep · 17 km away
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us7000q99p (also filed as usauto7000q99p, pt25179000). Read Sun, Oct 4, 2026, 3:06 PM UTC.